Located in a gigantic old factory, Mass MoCA reminds me of the Tate Modern in London: huge spaces filled with huge art. I could spend a whole day here, but I love weird art. (Monet-lovers aren't quite as enthralled). I was blown away by the Anselm Kiefer paintings, and loved the 3-floor Sol Lewitt retrospective, on view through 2033. (Hurry up!)